Tachymeter or speed indicator of the chronometric type with remote electric control



Oct. 26, 1937. c. H. H. RODANET 2,097,215 TACHYMETER OR SPEED INDICATOR OF THE CHRONOMETRIC- A TYPE WITH REMOTE ELECTR CONTROL Filed D60- 6, l

UNITED STATES PATENT OFFICE TACHYMETER OR SPEED INDICATOR OF THE CHRONOMETRIC TYPE WITH RE- MOTE ELECTRIC CONTROL Charles Hilaire Henri Rodanet, Neuilly-sur- Seine, France, assignor to Societe Anonyme Etablissements Ed. Jaeger, Levallois-Perret, France Application December 6, 1933, Serial No. 701,246 In France December 14, 1932 Claims. (Cl. 235-104) Tachymeters or speed indicators have been known for a long time, in which a wheel is driven by the shaft the speed of which is to be measured during a definite time, then released for return- Fig, 3 is an axial section made according to line III-III of Fig. 1.

In this arrangement, all the elements of a speed indicator of the chronometric type, accord- 5 ing to its position of rest under the action of a ing to the United States Patent No. 1,626,697 of 5 spring. An index or other indicating device is the applicant, are maintained, but the shaft l driven by the movement of the wheel, then rewhich, in the known device, is actuated by the tained by a pawl, and finally released, in such a shaft the speed of which is to be measured, is in manner that the index indicates, at each cycle, s C se ac d y a motor for instance the position reached by the driving wheel. an electric motor. 10

Previously, use was made of a clockwork, pref- The shaft I drives the wheel 3 through the erablyof the automatic winding up type,.for conmedium of the wheel 2. This Wheel 3 is controllihg the period of time during which the nected by a friction coupling to the ratchet wheel driving wheel was exerting its driving action. 4 of an anchor eso p te r ct on Cou- Then the applicant has proposed to avoid the use pling is more particularly shown in Fig. 3, in 15 of the spring barrel and of the automatic wind- Which it co p ses tWo friction plates 5 and 6, ing up device by the United States Patent No. s parat y a pr T W eel 4 of the 1,626,697 dated May 3, 1927. For that purpose, escapement is connected to the shaft 1 of the the shaft provided with cams ensuring the above driving Pinion 8 by a resilient device, Such as a mentioned functions was driven by the shaft the Spring a y Wheel 10 being rigidly Secured on 20 speed of which was to be measured, by means of the Shaft One end of the p n 9 is ona friction coupling, and the speed of the cam shaft neoted With the y W el was controlled by a, chron metri escapement, The anchor H is alternately drawn to one side The main object of the present invention cond the other by electromagnets l2 and I3 which sists in constructing the apparatus briefly deare energized by means of a switch 15 rotatively 25 scribed above in such a manner that it can indidriven by the shaft iii the speed of which is to be cate, without mechaniee connection with th measured. This switch energizes one or more shaft, but-only hy,electric. control, the number of times P revolution, s ve y, e e ect orevolut ionspenunitof timeof said shaft. magnets i n 3 Which attract e armature In'the knownapparatus previously indicated, fitted on the anchor In this a n 30 the energynecessaryfor the actuation of the intet hetwheel. 4 eifectsa number of revolutions dex on the one hand, and for the operation of proportional, to henum rof evolutions of the the chronometric escapement on the other hand, ft" he SDeedofUWhich .istobe measured. It was bo d from t shaft, t speed of which will be understood that, in this manner, the entire was to be measured. device operates exactly as if the shaft l was di- 35 According to the present invention, thi energy rectly driven by the shaft [5 the speed of which is is supplied by an independent meter, for in to be measuredstance an electric motor,'fthe'movement offthe. The movement of the ratchet wheel 4 is discondriving-wheel being synchronized with that (if tinuous. This ratchet wheel 4 is not rigidly se- 40 the shaft the speed of which is to be measured, cured on the shaft 1, as it is preferable that the 40 In fact, this driving wheel is intermittently actu shaft 1 should rotate as continuously as possible. ated, as explained,'by a pinion having a movable For obtaining this result, use is made of the fly shaft which must rotate at a speed proportional Wheel the inertia of Whioh egularizes the to that which is to be measured; in a ti it is movement of the shaft 1 which is driven through therefore the speed of rotation of this pinion, the medium of the resilient member 9. At the 45 called driving pinion, which is, according to the beginning of the actuation of the s t y th invention, synchronized with th speed t b ratchet wheel 4, the spring is tensioned, so that measured. the shaft 1 takes up speed but progressively.

The accompanying drawing illustrates, by way p pp e of the ratchet Wheel the Spring of example only, a. form of carrying the i venti 9 relaxes. It will therefore be seen that, in any 50 into practice. case, the spring assists the function of'the fly Fig. 1 is a diagrammatic perspective view f th wheel It). On the contrary, in a friction coupling device. the friction does not act in the same direction as Fig. 2 is an end view of the electromagnetic the fly wheel 10 when the ratchet wheel 4 stops.

synchronizing device. Itisobvious-tha-tanymeanscanrhehprovidedrfor 55 deadening the oscillationofthe resilient device.

The operation is as follows: When drive shaft I is operated by the electric motor I, it acts to drive gears 3 and H constantly in the same direction. Gear 3 acts through the friction coupling 56l' to operate shaft l and pinion 3 thereon, and the anchor escapement lH limits the speed of shaft 1 and pinion 8 at a rate proportional to the speed to be measured. Gear 3 also rotates gear H which drives cam shaft 42 through the medium of a slipping clutch, so that shaft 52 may rotate at a speed different from that of gear H and, hence, independently of the rate of operation of drive shaft l and the shaft 1.

The gear H is loosely mounted on the shaft 42, and a spring it bears at one end against the adjacent face of the gear Il For the sake of clearness, in Fig. 1 an auxiliary plate I! engaging the spring I5 is shown, but in practice the spring rests directly on the escapement wheel M.

Cam shaft 52 is controlled by the escapement mechanism 4346 so that each revolution of the shaft takes place in a predetermined unit of time. In the illustrative embodiment of the invention disclosed herein, the escapement mechanism is arranged to cause a rotation of cam shaft 42 to take place in 14 vibrations of balance wheel 45 which may correspond with a time interval of two seconds, for example. Thus a rotation or single cycle of operation of cam shaft is divided into 14 periods, as the escapement ratchet comprises seven teeth.

During the periods 1 to '7 the spring 55 acts on lever 56 causing engagement of pinion 8 with indexing wheel 52 so that in these seven periods, the wheel 52 is driven, and there is imparted to the latter an angular displacement corresponding to the speed to be measured.

Wheel 52 acts through stud 64 thereon, and the stud 65 carried by setting wheel Hi, to effect a corresponding displacement of said wheel 10, which indicates the speed of the, shaft l6.

It will be apparent that the operation just described takes place only when the tachymeter starts from its zero position or when the speed to be measured in a particular operating cycle of shaft 42, exceeds that of the previous cycle.

During the sixth period, cam 6| moves from contact with spring detent -and"the"latter"ena rs ingivheelltarorholdingit-m the positionjtiijv'vhich itisadvanced.bylpinion .8. At or towards the end of the seventh period, cam 5 3v engages lever Et operating the latter to rock shaft 7 in its swivel mounting inratchet wheel 4 so as to disengage pinion 8fromwheel52 Pinion 8 is maintained disengaged byncam lirthrough the eighth to 14th periods, or the remainder of the cycle.

During the seventh period, cam Tl disengages detent 16 from the setting wheel H! and spring 18 acts to move the latter reversely until the stud 66 thereon contacts the stud 64. Spring 18 may act during whatever portion of the seventh and eighth periods is necessary to engage stud 66 with stud 64. The new position of setting wheel 'Hl corresponds with that of the indexing wheel 52. The operations here described take place only when the speed of shaft i6 is less than that in the previous cycle.

In the event the shaft l6 has accelerated in a particular measuring cycle so that its speed exceeds that of the previous cycle, the indexing wheel 52 acting througlrstuct'fi, andstud'B'S on setting wheel ill will pickupthelatterat the time during the firstseven periods of the cycle when the instantaneous speed of the engine reaches and exceeds that attained in the previous cycle. Setting wheel 70 will then be carried along with indexing wheel 52 until the angular displacement of the latter in accordance with the higher speed in the cycle terminates at the end of the seventh period thereof, so that it immediately indicates the higher engine speed.

At the end of the eighth period, cam 11 moves from contact with spring detentlfi and thelatter (through periods one to seven) untilthe detent is again released theseventhlperiod of the following cycle for enabling readjustment of the wheel as described above.

During the ninth period, cam 6| moves detent 50 from engagement with indexing wheel 52 and, since pinion 3 is disengaged from the latter, a spring not shown acts to return the indexing wheel to its initial position. Said spring may act during whatever part of the ninth to 14th periods if necessary for causing wheel 52, to carry stop arm 6 3 into engagement with a fixed stud not shown so that the indexing wheel is brought to rest in its starting position. At the beginning of the first period of the next cycle cam 58 releases lever 56 and spring 56 acts thereon to again mesh pinion 8 with indexing wheel 52 so that the latter may be displaced angularly in proportion to the speed of the engine during the measuring periods of the cycle.

When the shaft it rotates at a constant speed for an interval of several cycles the indexing wheel 52 is repeatedly advanced in the early or measuring part of each cycle through a corresponding angular displacement until it carries the stud 54 into contact with the stud 66 on setting wheel Ill and is then returned to its initial position during the latter or resetting part of each cycle. Setting wheel lil having once been adjusted, as described above, to a position corresponding to the constant speed of the shaft l6, remains in that position until said shaft [6 again accelerates or decelerates, whereupon its positions are corrected to correspond with whatever change of speed takes place, as set forth previously.

From the foregoing description it may be seen that the speed of the shaft I6 is repeatedly measured at short intervals by effecting a proportional displacement of the indexing wheel 52 in e.earlxnarl.9?...93512.cyclenr eration. and tl fat,"v themeasurement is promptlytransferred to the.setting--wheel ill-for indicating the speed. The duration of the'timing interval is preferably sufiiciently short that the tachymeter does not lag appreciably in responding to indicate changes in the engine speed but affords a substantially instantaneous and accurate indication of the speed of the shaft [6 at any instant.

What I claim as my invention and desire to secure by Letters Patent is:

1. In combination, a rotating shaft, a tachymeter of the chronometric type for measuring the speed of said rotating shaft, said tachymeter comprising an indexing wheel, a driving pinion, a driving wheel for the driving pinion, a friction coupling for connecting the driving wheel to the driving pinion, means comprising a driving wheel for periodically producing the actuation of the indexing wheel by the driving pinion, a motor arranged for rotating more rapidly than the rotating shaft, means for affording a positive kinematic connection between said motor, the driving wheel of the driving pinion, and the second driving wheel, and means for synchronizing the speed of rotation of the driving pinion, with the speed of rotation of the rotating shaft.

2. In combination, a rotating shaft, a tachymeter of the chronometric type for measuring the speed of said rotating shaft, said tachymeter comprising an indexing wheel, a driving pinion, a driving wheel for the driving pinion, a friction coupling for connecting the driving wheel to the drivingpinion, means comprising a driving wheel for periodically producing the actuation of the indexing wheel by the driving pinion, a motor arranged for rotating more rapidly than the rotating shaft, means for affording a positive kinematic connection between said motor, the driving wheel of the driving pinion, and the second driving wheel, a wheel provided with abutments, means for operatively connecting said abutment wheel to the driving pinion, a stoplever cooperating. with the abutments of the abutment wheel, means controlled by the rotating shaft for periodically releasing the stop lever from the, abutment "wheel, a

3; In combination, a rotating shaft, a tachymeter of the chronometric type for measuring the speed of said rotating shaft, said tachymeter comprising an indexing wheel, a driving pinion, a driving wheel for the driving pinion, a friction coupling for connecting the driving wheel to the driving pinion, means comprising a driving wheel for periodically producing the actuation of the indexing wheel by the driving pinion, a motor arranged for rotating more rapidly than the rotating shaft, means for affording a positive kinematic connection between said motor, the driving wheel of the driving pinion, and the second driving wheel, an anchor escapement comprising an escapement wheel and an anchor, means for operatively connecting the escapement wheel to the driving pinion, means controlled by the rotating shaft for causing the anchor to periodically rock.

4. In combination, a rotating shaft, a tachymeter of the chronometric type for measuring the speed of said rotating shaft, said tachymeter comprising an indexing wheel, a driving pinion, a driving wheel for the driving pinion, a friction coupling for connecting the driving wheel to the driving pinion, means comprising a driving wheel for periodically producing the actuation of the indexing wheel by the driving pinion, a motor arranged for rotating more rapidly than the rotating shaft, means for affording a positive kinematic connection between said motor, the driving wheel of the driving pinion, and the second driving wheel, an anchor escapement comprising an escapement wheel and an anchor, means for operatively connecting the escapement wheel to the driving pinion, a magnetic armature secured on the anchor, two electromagnets acting in cooperation with said armature, and means controlled by the rotating shaft for alternately energizing each of the electromagnets.

5. In combination, a rotating shaft, a tachymeter of the chronometric type for measuring the speed of said rotating shaft, said tachymeter comprising an indexing wheel, a driving pinion, a drivingwheel for the driving pinion, a friction coupling for connecting the driving wheel to the driving pinion, meansicomprisinga driving-wheel r iirip i fl y. pliq dllqi l fihcactuation of .the indexingmwhee l by the driving pinion, a motor arranged for rotating more rapidly than the rotating' shaft, means for affording positive kinematic connection between said motor, the driving wheel of the driving pinion, and the second driving wheel, an anchor escapement comprising an escapement wheel with an anchor, a spring for Y operatively connecting the escapement wheel to CHARLES HILAIRE HENRI RODANET. 

